Soft tissue injuries are identified as a major source of pain and disability and occur across a wide section of the community. Generally, soft tissue injuries arise as a result of damage to muscles, nerves, connective tissues, fascia, joint capsules, periosteum etc as a result of excessive force/stress in a given moment, or repetitive strain placed upon these tissues over an extended period of time. As such, soft tissue injuries are very common in the work-place. Additionally, soft tissue injuries can occur as a result of trauma (eg resulting from sporting incidents and motor vehicle accidents); these injuries may not always be immediately obvious at the time of the trauma, but can become the cause of significant chronic pain at a later date.
Soft tissue injuries can be considered to comprise one or more fracture(s), because it involves the local separation of tissue (eg muscle, tendon or ligament tissue) into two or more pieces under the action of stress. Hence, damage to soft tissue can be interchangeably referred to as a “soft tissue stress fracture” or “soft tissue injury”. Commonly, the size of the fracture(s) may be relatively large (eg a tear of 0.5 to 3.0 cm), but in many instances, the fracture(s) may be of the microscopic scale (eg a tear of ≤2.0 mm, such as a tear of about 1.0, 0.5 or 0.2 mm, which may comprise one or more individual tissue fracture such as one or more fractures within collagen tissue). Nevertheless, both large and microscopic soft tissue injuries can lead to significant acute and/or chronic pain. At least in part, the pain is due to the body's inflammatory response to the injury. That response results from a complex cascade of events that includes changes to the concentration of various chemical components within the body, such as histamines, prostaglandins, cytokines etc along with the stimulation and/or proliferation of various inflammatory cells such as leukocytes, fibroblasts and macrophages, and can lead to a range of physiological effects mediated by an increase in inflammatory hormones and/or nerve chemicals at the site of injury. Such physiological effects may include swelling, hypersensitivity, neuritis, fasciculation, involuntary muscle contraction, heat, reduced blood flow and, critically, a reduced ability of the lymphatic system to drain interstitial fluid (lymphoedema). All of this can lead to a vicious cycle of pain for the patient.
Effectively treating pain arising from a soft tissue injury requires identification of the site of injury. This can be difficult since the region of the body where the patient perceives the pain to be present can be at some distance or even quite remote (ie referred pain) to the location of the causative soft tissue injury. Moreover, given their small size, soft tissue injuries can quite simply be very difficult to diagnose or pinpoint, especially with the lapse of time.
One approach to the detection of small tissue injuries is to use Magnetic Resonance Imaging (MRI). However, such equipment requires a detailed understanding of the symptoms of the injured person, his/her case history, and then, based on that information, very precise and localised use of the equipment to observe the injury. Moreover, the equipment used for this form of imagery is very expensive and cannot, therefore, be used on a day-to-day basis by general medical practitioners (GPs). Consequently, the use of MRI is not regarded as a practical or useful tool for the general diagnosis of soft tissue injuries.
An alternative approach is to look for and detect the inflammatory response at and around the site of a soft tissue injury. In his previous patent application, PCT/AU2011/000609 supra, the present inventor has described certain methods based upon this approach. In brief, such methods can involve initially obtaining a thermographic image (thermal image) of an area suspected of being associated with the patient's pain to enable visualisation of variation in surface temperature using an infrared imaging camera. This involves resolving the thermal image to reveal a “hot” area typically no more than about 2-5 cm in length or diameter that may point towards the region of inflammation (ie causing heat). However, since it can be difficult for a medical practitioner or therapist to match the hot area as indicated on the thermal image to the exact site on the patient's body and/or pinpoint the site of injury within the location corresponding to the hot area, it has proven insufficient to provide a reliable diagnosis or pinpointing of the site of injury based upon a thermal image alone. Accordingly, the methods described in PCT/AU2011/000609 further involve the application of electromagnetic (EM) energy or radiation to the location corresponding to the hot area through the use of, for example, a laser probe and thereafter obtaining the patient's feedback on the level of a warming sensation caused by the EM energy or radiation at each region or point of application. The site of the soft tissue injury corresponds to the region or point(s) where the sensation is warmest but not uncomfortable (eg a sensation rating of 6-8 on a scale of 1 to 10). Once the site of soft tissue injury has been identified in this way, the methods enable effective treatment through, for example, the further application of EM energy or radiation of suitable wavelength and intensity (eg “cold” laser therapy, otherwise known as low-level laser treatment (LLLT) and photobiomodulation (PBMT), known to be effective in the treatment of chronic pain such as that caused by chronic inflammatory conditions, wound repair and lymphoedema; Liebert A D et al., Medical Hypothesis 82(3):275-281, 2014) by a medical practitioner or therapist to the identified site of soft tissue injury.
While the methods described in PCT/AU2011/000609 have proven to be highly effective in detecting and thereby enabling the effective treatment of soft tissue injury, there is a desire to provide an improved methodology which is less operator-dependent and/or less reliant on verbal feedback from the patient being treated. The present invention is therefore directed at providing a novel method and apparatus for treating soft tissue injury which may address one or both of these issues.